diff --git a/server/gameserver/ability.cc b/server/gameserver/ability.cc
index 62630544..4b038205 100644
--- a/server/gameserver/ability.cc
+++ b/server/gameserver/ability.cc
@@ -539,7 +539,23 @@ void Ability::RecalcAttrRuduce(int attr_id)
         AttrRuduce* e = list_entry(pos,
                                    AttrRuduce,
                                    entry);
-        new_val += e->value;
+        switch (attr_id) {
+        case kHAT_Speed:
+            {
+                new_val = std::max(new_val, e->value);
+            }
+            break;
+        case kHVAT_Dmg:
+            {
+                new_val *= 1.0f - e->value;
+            }
+            break;
+        default:
+            {
+                new_val += e->value;
+            }
+            break;
+        }
     }
     std::get<0>(attr_dec_[attr_id]) = new_val;
 }